This proposal is for the purchase of a Faxitron UltraFocusDXA Digital Radiography System, which will add high resolution dual energy x-ray absorptiometry (DEXA) capabilities to our present imaging capabilities?providing better data on longitudinal effects on bone mass, fat mass, lean mass, and high resolution planar imaging with the use of fewer animals and in less time?and which will also help relieve pressure on our crowded scanning schedule. The laboratories interested in this piece of equipment are involved in a wide range of funded research programs, including bone metabolism, orthopaedics, cancer biology, diabetes, and obesity. With the UltrafocusDXA system, we will be able to scan the mice at a maximum of 48 m, and a minimum of 6 m, which will usher in the possibility to measure parts of the skeleton that we are currently unable to do. Using the high resolution planar x-ray capability, we will have the capability to screen mice for tumors, image skeletal fractures, and even assess cortical width and bone geometry. The bed size (camera/detector size) of the on the UltrafocusDXA system is much larger (10 X 15 cm) than the Piximus II system (currently obsolete but the only instrument available) and can accommodate a mouse of any size/weight/age, and even rats. The last mouse DEXA (Lunar's Piximus II system) unit was produced in 2005. Because Lunar shut down production of these research units, technical support is weak and parts are becoming very scarce for repairing the units. Acquisition of the recently introduced Faxitron UltraFocusDXA Digital Radiography System at our VA facility would allow us to get reliable service and parts for our DEXA scanning needs (in addition to better quality, faster, and more versatile capabilities). In addition, the UltraFocusDXA can be used to scan many of the specimens now being scanned on the old Piximus II system, with identical (or improved) parameters, and so relieve pressure on the present (inferior) instrumentation. There are numerous VA-funded investigators at the Indianapolis VA that would benefit greatly from acquisition of the Faxitron UltraFocusDXA Digital Radiography System, including Drs. Robling (osteoporosis), Moe (chronic kidney disease), Bellido (osteoporosis), Roodman (multiple myeloma), Nakshatri (sarcopenia/cachexia), Tholpady (craniofacial reconstruction), and Evans-Molina (diabetes/obesity).